Theory Code_Char

theory Code_Char
imports Char_ord
(*  Title:      HOL/Library/Code_Char.thy
Author: Florian Haftmann
*)


header {* Code generation of pretty characters (and strings) *}

theory Code_Char
imports Main Char_ord
begin

code_printing
type_constructor char \<rightharpoonup>
(SML) "char"
and (OCaml) "char"
and (Haskell) "Prelude.Char"
and (Scala) "Char"

setup {*
fold String_Code.add_literal_char ["SML", "OCaml", "Haskell", "Scala"]
#> String_Code.add_literal_list_string "Haskell"
*}


code_printing
class_instance char :: equal \<rightharpoonup>
(Haskell) -
| constant "HOL.equal :: char => char => bool" \<rightharpoonup>
(SML) "!((_ : char) = _)"
and (OCaml) "!((_ : char) = _)"
and (Haskell) infix 4 "=="
and (Scala) infixl 5 "=="
| constant "Code_Evaluation.term_of :: char => term" \<rightharpoonup>
(Eval) "HOLogic.mk'_char/ (IntInf.fromInt/ (Char.ord/ _))"

code_reserved SML
char

code_reserved OCaml
char

code_reserved Scala
char

definition implode :: "string => String.literal" where
"implode = STR"

code_reserved SML String

code_printing
constant implode \<rightharpoonup>
(SML) "String.implode"
and (OCaml) "!(let l = _ in let res = String.create (List.length l) in let rec imp i = function | [] -> res | c :: l -> String.set res i c; imp (i + 1) l in imp 0 l)"
and (Haskell) "_"
and (Scala) "!(\"\" ++/ _)"
| constant explode \<rightharpoonup>
(SML) "String.explode"
and (OCaml) "!(let s = _ in let rec exp i l = if i < 0 then l else exp (i - 1) (String.get s i :: l) in exp (String.length s - 1) [])"
and (Haskell) "_"
and (Scala) "!(_.toList)"


definition integer_of_char :: "char => integer"
where
"integer_of_char = integer_of_nat o nat_of_char"

definition char_of_integer :: "integer => char"
where
"char_of_integer = char_of_nat o nat_of_integer"

lemma [code]:
"nat_of_char = nat_of_integer o integer_of_char"
by (simp add: integer_of_char_def fun_eq_iff)

lemma [code]:
"char_of_nat = char_of_integer o integer_of_nat"
by (simp add: char_of_integer_def fun_eq_iff)

code_printing
constant integer_of_char \<rightharpoonup>
(SML) "!(IntInf.fromInt o Char.ord)"
and (OCaml) "Big'_int.big'_int'_of'_int (Char.code _)"
and (Haskell) "Prelude.toInteger (Prelude.fromEnum (_ :: Prelude.Char))"
and (Scala) "BigInt(_.toInt)"
| constant char_of_integer \<rightharpoonup>
(SML) "!(Char.chr o IntInf.toInt)"
and (OCaml) "Char.chr (Big'_int.int'_of'_big'_int _)"
and (Haskell) "!(let chr k | (0 <= k && k < 256) = Prelude.toEnum k :: Prelude.Char in chr . Prelude.fromInteger)"
and (Scala) "!((k: BigInt) => if (BigInt(0) <= k && k < BigInt(256)) k.charValue else error(\"character value out of range\"))"
| constant "Orderings.less_eq :: char => char => bool" \<rightharpoonup>
(SML) "!((_ : char) <= _)"
and (OCaml) "!((_ : char) <= _)"
and (Haskell) infix 4 "<="
and (Scala) infixl 4 "<="
and (Eval) infixl 6 "<="
| constant "Orderings.less :: char => char => bool" \<rightharpoonup>
(SML) "!((_ : char) < _)"
and (OCaml) "!((_ : char) < _)"
and (Haskell) infix 4 "<"
and (Scala) infixl 4 "<"
and (Eval) infixl 6 "<"

end